Characterization of Submerged Tolerant Elite Rice Genotypes Having Improved Physiological Traits and Oxidative Defense System grown under Rainfed Lowland Ecosystem of Eastern Indo-Gangetic Plains

Abstract

An experiment was conducted in 2014 and 2015 kharif season to evaluate the performance of rice genotypes under submerged condition on the basis of morpho-physiological traits and yield attributes. The study revealed that rice var. Swarna Sub 1 exhibited the highest survival (91.2%), whereas var. IR42 as susceptible check showed the least survival (4.2%) under submergence. Among the tested genotypes, IR 10F365, IR 11F216 and IR 11F239 with the respective survival values of 81.4, 80.0 and 78.1%, respectively, were found to be at par with the var. Swarna Sub 1 after 16 days of complete submergence at vegetative stage. Moreover, physiological traits like chlorophyll, sugar content and anti-oxidative system (SOD and CAT) were higher in tolerant genotypes as compared to susceptible ones. Less reduction in the content of sugar, chlorophyll, SOD and CAT activity was observed in genotypes IR 10F365, IR 11F216 and IR 11F239 along with var. Swarna Sub 1 (tolerant check) after submergence, while in susceptible genotypes IR 09L311, IR 08L216 and IR 55423-01 the reduction in sugar and chlorophyll content was higher just after submergence. Apart from physiological traits, tolerance genotypes have higher yield and yield attributing character as compared to susceptible genotypes. Thus, the study revealed that not only var. Swarna Sub 1 even few more elite rice lines found superior in terms of submergence tolerance and yield.